Are you talking about Eco-complete(which comes soaking in ferts) or the buffering substrates (amazonia, fluval plant & shrimp stratum, etc) that are popular with caridina shrimp?
His gravel looks just a bit larger than mine.
I manage to get by with just gravel in my spec. I added just bit of osmocote and it was all good, tho the s. repens and a small patch of micro sword are the only rooting plants in the gravel.
I considered completely overhauling my neighbor's spec v with flora max capped with her gravel while I was looking after her tank, but I was too lazy. Flora max is kinda hard to plant in too, it's so crunchy.
Sand/blasting sand looks nice, but what are you putting that over BettaBettas?
I believe there's more than a few types, I don't recall all of their names. ADA makes a substrate I was thinking of in particular.
Particle size since we're on mnemonics,
I have liked and used a 'gravel' that's a mix of washed river sand and turkey grit, Since the stuff I source is washed down from the PacNorwest Cascade Mountains, it's mostly igneous rock gravel from old lava fields and flows. It's about 1mm to 5mm in size, with more fine sizes predominating. It's also darn pretty with lots of browns, reds, Ocher/black and mottled greys.
The problem with Alex's gravel is that it's got really large voids between the pieces, which will hide and trap uneaten food, fish poop, dead plant material, and will be harder to clean effectively. There also the chance, especially if this tank is used for shrimp, that any planarians that make it in, will be in hog heaven because of the trapped food. Of course you can always treat for them.
Finer grained gravel tends to collect the mulm and debris on it's surface where it can be more effectively vacuumed, so there is less chance of fouling the gravel, plus smaller rooted plants readily take to growing in this kind of 'soil'. It's more work to find but less expensive to purchase and looks more natural.